Last month, The Social Network screenwriter Aaron Sorkin told the Harvard Crimson that “[a]ttention to truth and attention to detail were incredibly important” to himself and director David Fincher. By way of example, Sorkin explains that the filmmakers went to great pains to discern what “kind of beer [Facebook founder Mark Zuckerberg] was drinking on a Tuesday night in October seven years ago.” In reality, the name of the beer—Beck’s— can be uncovered with a simple Google search. Sorkin’s sincerity is harder to locate. In a New York magazine article headlined “Inventing Facebook,” he makes a different claim about his honest intentions: “I don’t want my fidelity to be to the truth; I want it to be to storytelling.”

After watching The Social Network, it’s obvious that Sorkin’s second, truth-abdicating quote is the one worth believing. The Social Network has been likened to Rashomon, the Kurosawa classic that plumbs a singular truth from multiple perspectives. But Sorkin and Fincher aren’t just exploring different viewpoints in a dispute. They’re manufacturing a fictional reality from real-life events.

The half-truths begin with the movie’s opening scene, in which the famously maladroit Zuckerberg goes full Asperger’s on his girlfriend, who proceeds to dump him with a series of sharp-tongued, Sorkin-ian retorts. Burning with vengeance, Zuckerberg hacks into Harvard’s servers to grab students’ images, then codes a site called Facemash that allows users to rank the photos by attractiveness. This incident, in Sorkin’s mythologizing, provides the emotional underpinnings for the birth of Facebook. A spurned geek seeking girls and status launches a photo-ranking site that morphs into a social-networking site, giving him the standing online that he never had in the physical world.

While this fantasy works nicely on the big screen, it’s pretty much hooey. Counter to its depiction in The Social Network, the real Facemash included photos of both men and women—a fact that cuts against the depiction of Zuckerberg as a horny dude out for revenge. As for the notion that Zuckerberg was scorned by a girlfriend, Sorkin’s source material appears to be the blog the Facebook founder kept while coding Facemash. In the journal, Zuckerberg wrote, “Jessica Alona is a bitch.” The Social Network changes Jessica Alona to Erica Albright, the supposed girlfriend (played by Rooney Mara) who dumps Zuckerberg at the beginning of the movie. It’s unclear, however, that the real Jessica Alona was Zuckerberg’s girlfriend or that they had any kind of relationship at all—she’s never come forward and no reporter has ever interviewed her on the record or seemingly even tracked her down.

Nevertheless, after the Facemash journal surfaced, some media outlets made the unfounded assumption that Zuckerberg’s anger toward Alona inspired Facebook. Ben Mezrich, the author of the 2009 book The Accidental Billionaires and an admitted truth-stretcher, went even further, saying the Alona moment “inarguably led to one of the greatest fortunes in modern history.” If you believe Mezrich, however, you have to believe that Facemash—a hacked-together takeoff on Hot or Not—was the inspiration for Facebook, a site with an entirely different concept and functionality. (And if you believe that, it’s worth noting, you’re carrying water for Zuckerberg’s legal team. Zuckerberg’s lawyers have been pointing to Facemash for years as a defense against accusations of intellectual property theft brought by Cameron and Tyler Winklevoss and Divya Narendra, the Harvard students who hired Zuckerberg to work on their own social network before Facebook even existed.)

Mezrich’s book was optioned for the screen in 2008 by The Social Network producer Scott Rudin when it was nothing more than a thin proposal. The proposal added another questionable brushstroke to the already questionable Jessica Alona back story: In Mezrich’s telling, Zuckerberg dreamed up Facebook to get laid and to get back at the Harvard elites who shunned him, a motivation that Zuckerberg has denied and for which there is no evidence. While the proposal’s confident assertion that Zuckerberg craved admission to Harvard’s haughty final clubs was toned down when The Accidental Billionaires went to press, Sorkin makes a dorky Zuckerberg’s yearning for cool-guy acceptance the centerpiece of The Social Network.

The movie alleges that Zuckerberg and his best friend (and Facebook co-founder) Eduardo Saverin fell out, to a large extent, because Saverin was “punched” for the elitist Phoenix club, which the movie fatuously represents as a lusty den of vice where gorgeous co-eds dance in their underwear on tables for lecherous clubmen. This is a world Zuckerberg can’t access, according to Sorkin. As The Social Network accurately depicts, Zuckerberg forced Saverin out of Facebook, and Saverin sued Zuckerberg. The dispute between Zuckerberg and Saverin has been litigated to such an extent that we may never know the exact truth of how Zuckerberg felt about his friend. This impasse is something The Social Network banks on. You can’t question what you can’t know. You can, however, write a story about it.

Ultimately, both Sorkin and Mezrich are responsible for The Social Network’s storytelling. While Sorkin has denied looking at The Accidental Billionaires as he wrote his script, the Mezrich book is listed as source material in the movie’s opening credits. There are also scenes in the movie that couldn’t have come from anywhere but Mezrich’s book. The Social Network leaves out some of The Accidental Billionaires’ most inflammatory material—you won’t see Zuckerberg and Saverin feasting on koala meat on a yacht in San Francisco, for instance— but much of Mezrich’s juiciest, least substantiated material reappears in the film. The wild scene in which computer-science groupies approach Zuckerberg and Saverin for sex in bathroom stalls remains. So does a concocted scene in which the Winklevosses and Narendra learn about Facebook’s expansion into Europe in the summer of 2004, when they’re at England’s Henley Royal Regatta. Facebook hadn’t crossed the Atlantic at that point.

Sorkin, too, bends truth to narrative. He adds anachronistic references to MySpace. He invents a scene in which early Facebook investor Sean Parker happens upon Zuckerberg’s rental house in Palo Alto, Calif., only after a zip line tears off the chimney. And Sorkin creates a climactic, computer-smashing confrontation between Saverin and Zuckerberg that I’ve been unable to find any reference to in the various Facebook lawsuits.

Let’s accept petty deceptions like these as a necessary ingredient in a dramatized story. The problem is that Sorkin doesn’t gloss over facts to get at any truths about Facebook’s founding. He is trafficking in dramaturgy.

The Social Network’s most honest moment comes in the movie’s closing scene, when a lawyer played by my Harvard classmate Rashida Jones tells Jesse Eisenberg’s Mark Zuckerberg that she doesn’t think he’s a jerk. It’s just that, as she puts it, “creation myths need a devil.”

Sorkin, too, has left us with a myth, and the mythmaker has washed his hands of the mythmaking process. Some critics call this a brilliant meta-disclaimer, an acknowledgment that there is no universal truth in the Zuckerberg story. It’s not. It’s an abdication of responsibility for a story that pantomimes Zuckerberg and is poised to transform Mezrich and Sorkin’s version of reality into whatever passes for truth these days.

Alas, here’s the rub: The Social Network is also a lot of fun. Go buy a ticket. Just don’t buy the story.